Safety shutter for moving-picture machines



7 1 J. I 9 1 N N A M E L H U F 2 9 1 April 22 S AFETY SHUTTER FOR MOVING PICTURE MACHINES Filed June 5, 1920 Patented Apr. 22, 1924.

UNITED STATES PATENT OFFICE.

THEODORE F. UHLEMANN, OF NEW YORK, N. Y., ASSIGNOR TO NICHOLAS POWER COM- PANY, 1116., OF, NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SAFETY SHUTTER FOB MOVING-PICTURE MACHINES.

Application filed June a, 1920/ Serial no. seams.

T all whom it may concern:

Be it known that I', Tnnononn F. Unw- MANN, a citizen of the United States, and a resident of the city, county, and State of New York, have invented new and useful Improvements in Safety Shutters for Moving-Picture Machines, of which the following is a specification.

his invention relates to safety shutters 1 for moving picture machines, and has for its object to provide a shutter which will autocut off the light from. the filmmatically on any irregularity in the feed of the film past the aperture as effected by the intermittent sprocket.

A further object of the invention is to provide a safety shutter of this class which is of simple construction, takingu but little room on the machine and of lbw manu- 2 facturing cost, and which may be readily to accidental displacement through vibration of the machine or other cause.

My improved safety shutter also embodies other advantages Which will be more apparent from the following specification when taken in connection with the accompanying drawings, wherein I have illustrated two different embodiments of my invention as ap lied to machines of different types.

11 said drawings a Fig. 1 is a side elevation of-a portion of a moving picture machine of the enclosed type showing the application of my improved shutter thereto, the machine casing being shown in section;

light the'thrust, but which will not be liable Fig. 2 is a vertical sectional view on the? Fig. 5 is a vertical sectional view showing the application of the shutter to a machine of the open type.

Referring to the drawings, particularly to Figs 1-4, 1 indicates the casing of the machine whlch comprises a rear .wall 2, usually arranged to open and close, and carrying tension shoes 3 which hold the film in lace at the aperture 4 when the machine is in operation.

The film is fed past the aperture by an intermittently operated sprocket 5 sup. orted in the frame beneath the aperture p ate 6. The ordinary commercial machine is also provided 'wlth a continuously operating sprocket 7 supported above the aperture for drawing the film off of the supporting reel and maintaining a loop of film as indicated. at 8 above the aperture plate to relieve the strain on the film which would be imposed by the direct action of the intermittent sprocket.

Fig. 1 shows the a proximate size of the loop usually employe the film bein guided upward from the sprocket by a gui e roller 9 and is then loope back past the marginal guide, rollers 10 which direct it to the aperture plate agitinst which it is held by the shoes 3. Int e construction shown, the tension shoes 3 and the marginal guides 10 are carried by a frame 11 attached to the inner face of the door 2, the frame consisting usually of a plate having a light aperture registering with the aperture in the door 2 and supporting on each side of the aperture the necessary brackets for the tension shoes 3.

The construction so far described constitutes the ordinary arrangement of the film feeding and guiding devices in a machine of the enclosed type. In applying my improved shutter to a machine of this kind I preferably employ a sliding shutter 13 such as shown detached in Fig. 4 and arrange the same to slide vertically across the aperture in the door 2, the shutter being interposed between the late 11 and the door, to which end the rear ace of the"plate will thickness sufiicient to allow the s utteiyto move freely between the plate and 'the door I 2 of the casing." Of course, if desired, the

plate may be spaced from door by sepa;

rate strips attached to the mar in of the plate instead of forming the gui es integral with the plate.

The upper part of the shutter 13 is imperforate throughout an area suiliciently large to cover the aperture when the plate is in its lower sition, and as shown the lower portion of t 6 plate is cut away at the middle to uncover the aperture when the plate is elevated as shown in Fig. 3, the shutter projecting down on each side of the guideway portion to better guide the plate in its movement, although it will of course be obvious that the shutter need be no longer than the imperforate portion.

The margins of the plate 11 extend above the plate proper to form brackets for supportlng the edge guides 10 and above the edge guides there is preferably a transverse strengthening bar 15 which I utilize for supporting the film-engaged part 16 of my safety shutter. As here shown, the part 16 comprises a sheet metal guide wider than the film and curved to conform to the usual loop 8 but to be clear thereof when the machine is operating in the proper manner and the loo does not assume abnormal proportions. he guide 16 is pivoted on a cross pin 17 supported on top of the bar 15, and

is spring-held toward the loop by a light spring 18, the movement of the guide toward the loop being limited by a pin 19 which is engaged by a hook 20 attached to the lower end of the guide beneath its pivot. When the hook is in engagement with the pin it is in position for its end to yieldingly engage in a notch 21 cut in the face of the shutter, the notch being positioned to maintain the shutter in its upper position clear of the aperture when engaged by the hook. This shutter 13 is preferably maintained in place and its extent of movement limited by means of a lateral extension 22 which projects through a slot cut in one of the raised margins of the plate 11, as shown in Figs. 1 and 4. When the plate is screwed against the door the shutter will be maintained in place, but its free movement within the desired limits will not be hindered.

The end of the extension 22 is preferably bent out to form a hook 23 to facilitate lifting the shutter back into engagement with the hook 20 when i has been released by an undue enlargement of the film loop. To permit the shutter to be re-set when the casing is closed there is preferably provided a tn arm 24 projectin through a slot in the oor 2 and connecte at its inner end to the hook 23 by a suitable link. When the casing is opened the hook 23 may be engaged directly by the operator to lift the shutter.

The operation of the device will be abvious from the above description. The curve of the guide 16 is such that any undue enlargement of the loop 8 as results from failure of the intermittent feed below the aperture and the continued 0 ration of the upper sprocket will cause a t rust of the loop against the face of the ide in a direction to release the hook 20 om the notch 21 in the shutter. A very slight thrust of the film is 'sufiicient to release the shutter, for all the parts, including the shutter, may be constructed of light sheet metal so that they will be held in place against displacement by a very light s ring. A very slight movement of the gui e is sufficient to release the hook 20 and when released the shutter falls freely of its own weight, bringing its imperforate portion across the a ture and cutting off the light from the 1m.

Cutting off the light immediately calls the operators attention to the irregularity in the feed so that he may open the casing and investigate the cause of the trouble. Preferably, however, before opening the casing the operator will ress down on the arm 24 and raise the s utter momentarily to uncover the aperture, immediately releasing the arm so that if the fault in the feeding has corrected itself, as not infrequently happens, the shutter will be caught and held by its hook, but if not, the shutter will again immediately fall, closing the aperture before the light from the projecting lantern can ignite the film.

I have illustrated the safety shutter as applied to a well known type of open machine. In this type of machine the tension shoes 25 are supported by a frame 26 attached to the face of the gate 27 in position to hold the film in place when the gate is closed. The frame 26 carries a plate 28 which, in machines of this type, is usually extended above the gate in the form of a cup-shaped hood or guide 29 to enclose and protect the loop of film. The shutter 30 is attached to the machine in the same manner as described above, that is, the plate 26 is removed from the gate and its rear face cut away to provide suitable guides for the shutter. The edge of the shutter projects above the top of the plate 26 in position to be carried by a hook 31' connected to the lower end of a guide 32 pivoted in the housing 29 in the same manner as the guide 16, the hook 31 projecting through a slot in the lower edge of the guide. The operation of the safety shutter when applied to a machine in the manner disclosed in Fig. 5 is the same as above described in connection with the closed machine. By forming the guide 32 separate from the housing 29 it may be made of very light material so that the shutter will be positively operated by the thrust of the film.

It will of course be understood that the details of construction may be otherwise modified than described to adapt the shutter to difierent types of machines.

I claim: 1. Asafety shutter for movin picture machines comprising a movab y mounted shutter adapted under the influence of gravity alone to assume a position to coverthe li ht aperture and cut off the light from the fi m, means for positively supporting said shutter in a fixed position clear of the light opening, and means for releasing the shu ter comprising a trip mounted adjacent the pgth of movement of the film in position to engaged and operated to release the shutter upon an abnormal departure of the portion 0 the film above said aperture from its proper path of movement.

2. A gravity-operated shutter for moving picture machines com rising a movably mounted shutter ada te in its normal position to cover the lig it aperture and cut oil the light from the film, means for fixedly supporting saidshutter in a position clear of the light opening, and means for releasing the shutter comprising a trip adjacent the path of movement of the film in position to be engaged and operated to release the shutter upon an abnormal chan e in the size of a slack loop provided in e film, the shutter dropgiing into closed position under the action 0 gravity.

3. In a moving picture machine, the combination of a frame part having a projection aperture, a gate to be closed against said aperture having guide shoes for maintaining the film in position at the aperture and a sliding safety shutter carried by said ate adapted under the influence of gravity a one to assume a position to cover the light a ert'ure and cut off the light from the 1m, means for supportin said shutter in a posi-. tion clear of the lig t opening, and means for releasing the shutter comprisin a trip also carried by said gate adjacent tie path of movement of the film in position to be engaged and operated to release the shutter upon an abnormal departure of the portion 0 the film above said aperture from its proper path of movement.

4. In a moving picture machine, the combination of a frame part having a projection aperture, film-feedin movement for advancing the film ast sai aperture, a casing enclosing sai aperture and film-feeding mechanism, a slidin safety shutter within said casing, means or effecting the operation of the safety shutter to cut ofl the light from the film com rising a trip arranged within the casing adjacent the path of movement of the film to be operated b an abnormal departure of the ortion o thefilni above said aperture from 1ts prescribed path of movement, whereby the shutter drops into closed position by the action of gravity, and means operatable from without the casing for re-setting the shutter after an operation of the shutter through the trip.

5. In a moving picture machine, the ombination of a part having a li ht opening for the passage of light to the film, a gravity-operated safety shutter for said opening comprising a shutter, member mounted for -free sliding movement in a vertical plane and adapted in its lowermost position to cover said opening, and means for normally fixedly supporting said shutter in a position clear of said opening comprising a movable trip engaging said shutter member having a part arranged adjacent the normal path of movement of the film in position to be shifted by the film to release said shutter 'upon an abnormal departure of the portion of the film above said aperture from its prescribed path of movement, said shutter u on release sliding by the action of gravity into closed position.

6. In a movingpicture machine, the combination of a film-moving mechanism, a casing enclosing said mechanism, said casing having an opening for the passage of light to the film, a safety shutter for said light opening comprising a shutter member supported within the casing for free vertical movement adapted in its lowermost position to close said light opening, means for normally sup orting sald shutter member in a position 0 ear of said light opening, said means comprising a pivoted trip having a hook to engage and support the shutter member with a small area ofcontact and a film-en aged part within the casing adjacent the pat of movement of the film in position to be engaged by the film upon an abnormal departure from its prescribed path and shifted by the film' to release said shutter, and means without the casing for shifting the shutter from the closed position into position to be en aged by said trip.

Signed at New ork, in the county of New York and State of New York, this 23rd day of December, 1919.

THEODORE UHLEMANN. 

